Patch vulcanizing apparatus



April 18, 1950 A. D. SLATKIN PATCH VULCANIZING APPARATUS Filed Feb. 16, 1946 v V 5 m I. RK/Y IA 7% 2 I- T as T mm A A ID E R r- MM 6 2 m 7 m m m 5 M5 I /Q/.. 143 .J a 4 I, s v 4 2w 7 3 F G a 4 r. .2 m$\ M Q 3 .0 M F 2 A 2 m m Patented Apr. 18, 1950 UNITED STATES PATENT OFFICE PATCH VULCANIZING APPARATUS Alfred Daniel Slatlrin, Toronto, Ontario, Canada Application February 16, 1946, Serial No. 648,070

7 Claims. 1

This"invention relates to patch vulcanizing apparatus.

Inthe vulcanizing of patches on inner tubes and other rubber articles, it has previously been proposed to apply the patch and to place over it a small metal pan carrying ignitable material which upon being ignited'b-urns for a short time and produces the necessary heat to efiect the vulcanization. This is a-substantiallyquick way'of vulcanizing a patch on rubber goods. iiov'lever, it has a substantial disadvantage,- which resides in the fact that'th'e heat generated is substantially intense and greater "than that required to effect the vulcanizing in question, so that in such a vulcanizing operationrubb'er is often deteriorated due to the heat.

Moreover, it has a further disadvantage through thefact'that sparks' tend'to fly which makes the apparatu'shazardous particularly as the apparatus is mainly used where inflammable materials may bepresent.

It has also been proposed'to efiect patch vulcanizing and the like by heat produced electrically and-whereby the ele'ctricmeans is controlled-by meansof a fuse which will burn out at a given temperature. Usuallythe fuse is part of a light metal'plate carried by each patch and which is adapted to form the continuity of circuit or the patch'is accompanied by a separatefuse which is inserted in the vulcanizing machine for each patch applying Operation. In the first case, a rather expensivepatch results apart from the added diiiiculty of removing the metal from the patch at the completion of the operation. Inthe second place, needless operation is necessary While the mechanism is intricate and relatively expensive.

These, disadvantages of prior practice are avoided by the present invention which presents a simplified structure heated electrically.

It is an object of the present invention to pro vide a patch vulcanizing apparatus which will vulcanize patches quickly and eficientl and wherein the heat is controlled so as to effect the vulcanizing operation without overheating. tend= ing'to injure or deteriorate the rubber material.

A'further object'of the invention is to provide afi apparatus of this kind which will operate automaticall to control the degree of heat each time that the apparatus is used.

[A iurther object of the present invention isto providea particularly simple apparatus of this l i-in "andemployinganoVeI thermostatic control mesns wnich immediately cut out the electric element when the required heat has been obtained and which is set'for'operationimmediately'that the patch applying accessory thereof is mounted.

in the machine fora patch applying operation.

With these and other objects in view the invention'generally comprises a casing embodyingan electric heating element designed to concentrate heat on a given area of the apparatus, a, patch applying plate designed to be mounted over the heat concentrated area, a thermostatic switch connected in the circuit of the heating element designed to open at a given temperature to break the circuit, a means of automatically locking" the thermostatic switch in open position' and means operable by the patch applyin plate forunlockin'g said switch and closing the circuit whensaid plate is positioned in the apparatus and operative for patch applying.

The invention will be clearly" understood by reference to the following detailed specification taken in conjunction with the accompanying drawings.

In the drawings,

Fig. 1 is a longitudinal section taken through one "form-of patch applying apparatus according to the present invention.

Fig. 2 is'a transverse section taken through Fig. 1 just above the top of the casing-to show the general manner in which the patch applying plate is related to other parts of the apparatus.

Fig. 3 is a fragmentary sectional detail of the actuating plunger operable to unlock the thermostatic switch, the'plunger being shown in normal position when the apparatus is not in use, and

Fig. 4 is a, similar view to Fig. 3 showing the plunger inoperative position when the apparatus is in use.

Referring to the drawings, A indicates the-vulcanizing apparatus as a whole according tothe present invention which includes a casing I 0 or other suitable support which may conveniently be rigidly carried and projected from a suitable mounting base H. The upper face of the casing I0 is formed with a suitable recess !2 of predetermined area positioned to encompassthe area of the largest patch which is desired to be applied. Therecessed area l-Zi disposed directly Over an electric heating element l3, thecasing l0 preferably being open,in the area of the'recess'l2 and heating element I3, such as indicated at M; to permit concentratin of the heat upon a'patch applying plate i5 designed to fit within the recess I2 when placed therein and being'readil-y removabl-e' therefrom.

The patch applying plate leis designedto re-- ceive-a suitable patch it over which an'innei' According to the present invention, the heating 1 element is connected by means of the leads 2t and 2| of and suitable conductor cable 22 and one of these leads, here shown as lead 2!, is connected in series with the opposed-arms 23 and 24 of the thermostatic switch which employs the 1 contacts 2'5. These contacts are normally designed to be closed as the patch is disposed in practical contact with the rubber article to be vulcanized at the start of the operation, and when the electric element l3 has been heated to the proper degree to effect a practical vulcanizing, the arm 24 of the switch which is chosen of suit-- able bimetal characteristics is designed to move away from the arm 23, thus to separate the contacts 25. Accordingl", the circuit to the heating element I3 is broken. However, with any drop in heat du to the breaking of the circuit the arm 24, if unrestrained, would return to normal psi-- tion and again set the heating element in operation. This is automatically prevented under the present invention. In this connection, a spring locking'element 26 is suitably mounted within the casing, as shown in Fig. 1, and may be secured by a suitable anchoring screw 21. The latching element is formed with a locking tongue at downwardly and forwardly sloped so that its extreme free edge slightly underlies the extreme free end of the switch arm 24. Consequently, as the switch arm 24, under the concentration of heat from heating element [3, moves away from the switch arm 23 to break contacts 25, the end of switch arm 24 will slightly depress the tongue 23 of the latch member 26 so that the end of the switch arm will pass the tongue and then will be retained by the end of the tongue from returning to normal position closing contacts 25. Accordingly, the heating element is shut off at the proper temperature and the vulcanizing operation is carried out under proper heat conditions without possibility of deteriorating the rubber due to excess heat. A suitable adhesion shield l3 may be employed between element [3 and the switch arms 23 and 24.

When the vulcanizing operation has been completed, the clamping plate I9 is raised and the vulcanized article is taken out with the patch it properly vulcanized thereon. Then, in order to proceed with a further vulcanizing operation, it is necessary to remove the patch applying plate l5, apply to it a new patch and reinsert the plate IS in the recess [2 of the apparatus. In this case, it will be apparent that the switch arm is held separated from the switch arm 23 so that the contacts 25 do not meet. In order to cause closing of the contact 25, I provide a means which will function automatically to achieve this result when the clamping plate l9 has been pressed onto the rubber article so as to engage it practicably with the patch l6.

Adjacent to the periphery of the recess 12, I mount a plunger or actuator 29 designed to have a main vertical or axial movement, but also so mounted that it can swing slightly from vertical position' The plunger is spring mounted preferably by means of a leaf spring which may also be anchored by the mounting screw 21. This spring is slotted or otherwise recessed to engage a preferably reduced portion 3| of the plunger, the upper end of which is always disposed within the confines of the guide orifice 32 disposed in theupper portion of the casing it within the recess [2. Normally, when the apparatus is not in use", the plunger is in the position shown in Fig. 3 with the upper end of the plunger projecting substantially past the top surface of the casing l9 within the recess l2.

The lower end of the plunger 29 is formed with a preferably conical foot 33 being formed with the sloped surface disposed upwardly and a fiat face disposed downwardly. The latter is designed partially to overlie the latch 25 when the plunger 29 is in the raised position. Consequently, as the article to be vulcanized is disposed in firm en' gagement with the patch Ila carried on the patch applying plate l5, the latter is caused to depress the plunger 29 because it is so positioned that an edge of the patch applying plate must be disposed to engage the plunger when the plate is properly disposed within the recess l2. As a result, therefore, when the plunger 29 is depressed the foot thereof will depress the latch member 26. thereby releasing its tongue 28 from engagement with the switch arm 24 so that the latter will spring back to normal position closing the contacts 25.

As has been stated above, th orifice 32 is so formed that a small amount of swingable movement is permitted plunger 29, and the conical portion 33 of plunger 29 is so disposed that a sector of its base overlies a portion of one side of latch member 26. The amount of swingable movement permitted is so small that it is impossible for conical portion 33 to depress latch arm 26 sufficiently to enable the conical portion to slip off the arm as long as the transverse axis of the latter is substantially horizontal, During the first part of the downward movement of plunger 29, latch member 25 bears against the bi-metallic strip 24, and is held with its transverse axis substantially horizontal by means of said strip. However, when latch member 26 has been sufliciently depressed to free the bi-metallic strip, the further depression of latch member 26 not only causes its tongue 28 to move further downward, but also causes the transverse axis of the said latch member to rotate, whereby the plunger is permitted to slip oil the latter and assume the position shown in Figure 4. With the closing of contacts 25 as described, the vulcanizing operation automatically proceeds, since the heating of the element I3 is brought into opera.-

tion, and when the predetermined heat has been reached the switch arm 24 is again caused to swing outwardly from the switch arm 23, thereby to break the circuit, and it will be locked in this position by means of the tongue 28 of the latch member 26.

When the vulcanized article is removed, the spring 30 returns the plunger 29 to the position shown in Fig. 3, since upon removal of the plate l5, or alternatively, the release of the pressure on the plate the spring 39 will naturally move the.

plunger 29 upwardly. Moreover, due to the conical or sloped upper surface of the foot 33 and the fact that the plunger 29 is mounted in the spring at so as to permit swinging movement as well as axial movement, the foot will be deflected by the conical surface thereof as it engages the edge of the latch member 26, thereby to return to normal opening l4 at the bottom of the recess I2 is bridged by the intermediat ribs 34 and 35 respectively. They are designed to perform the same function as the peripheral ledge 36 at the edg of the recess I2, namely, to support the edge of the patch applying plate. Therefore, in the case of a smaller patch applying plate, the rib 34 is positioned to support the edge of the next size of plate while the rib 35 is disposed so as to support a smaller sized plate. Thus, one edge of the patch applying plate I is supported either by the ledge 36 or ribs 34 or 35, while the other edge of the plate is positioned so as to depress the plunger 29 as shown in Fig. 1.

' The recess [2 is given a predetermined shape preferably and the patch plate IS a corresponding shape to make it necessary that a proper patch applying plate is used and to avoid any tendency to employ makeshift plates which might not operate satisfactorily. In the present illustration, the patch applying plate is substantially elliptical.

It will be apparent from the foregoing, that l have produced a simple apparatus which will act automatically to vulcanize at a controlled temperature and wherein the heating element is cut oil at a predetermined temperature, automatically and successively as the apparatus is used the switch is retained out of operation so that it cannot function again until a further vulcanizing operation is to be performed and the parts required are positioned properly for the operation.

What I claim as my invention is:

1. Patch vulcanizing apparatus comprising a support, an electric heating element mounted on said support, a patch applying plate mountable on said support adjacent to the heating element and designed to be heated thereby, said plate being adapted to carry a patch to be vulcanized to a rubber article, electric conduit means connected with said heating element and forming part of an electrical circuit for heating said element, a thermostatic switch in connection with said conduit means designed to open when said heating element is heated to a predetermined degree, thereby to break the circuit, means for locking said switch in open position as it opens, and means for actuating said locking means to release said switch whereby to cause it to close, said actuating means being located on said support in the area designed to receive said patch plate and being engageable by the latter when placed on the support and caused to press the patch against the article to be vulcanized.

2. Patch vulcanizing apparatus comprising a support, a heating element carried thereby, said support being recessed over an area in its upper surface above said heating element, a patch ap plying plate mountable in said recess to overlie the heating element designed to be heated therer by, said plate being adapted to carry a patch to be vulcanized to a rubber article, electric conduit means in connection with said heating element designed to form part of an electrical circuit for heating the element, a thermostatic switch in connection with said conduit means designed to open when said heating element is heated to a predetermined degree thereby to break the circuit, means for locking said switch in open position as it opens, actuating means for causing said locking means to release said switch whereby to cause it to close, said actuating means being operable from said recessed portion of the support and being engageable by said patch plate when disposed in operable patch applying position.

3. Patch vulcanizing apparatus comprising a support, a heating element carried thereby, said support being recessed over an area in its upper surface above said heating element, a patch applying plate mountable in said recess to overlie the heating element designed to be heated thereby, said plate being adapted to carry a patch to be vulcanized to a rubber article, electric conduit means in connection with said heating element designed to form part of an electrical circuit for heating the element, a switch connected to said conduit means and including a pair of arms, one of which is a bi-metal arm, said arms having contacts normally held in engagement to complete the circuit, a latch member carried by said support adjacent to said bi-metal arm and partially in the path of movement of one end thereof, said bimetal arm being caused to move away from said other arm to break said circuit when said heating element is heated to a predetermined degree, said bi-metal arm as it moves engaging and partially lodging behind said latch member to lock said switch in open position, and actuating means movable to engage and actuate said latch member to release said arm when said circuit is to be closed, said actuating means being operable from the recessed portion of said support and engageable by said patch plate when disposed in operable patch applying position.

4. Patch vulcanizing apparatus comprising a support, a heating element carried thereby, said support being recessed over an area in its upper surface above said heating element, a patch applying plate mountable in said recess to overlie the heating element designed to be heated thereby, said plate being adapted to carry a patch to be vulcanized to a rubber article, electric conduit means in connection with said heating element designed to form part of an electrical circuit for heating the element, a switch connected to said conduit means and including a pair of arms, one of which is a bi-metal arm, said arms having contacts normally held in engagement to complete the circuit, a latch member carried by said support adjacent to said bi-metal arm and partially in the path of movement of one end thereof, said bi-metal arm being caused to move away from said other arm to break said circuit when said eating element is heated to a predetermined degree, said bi-metal arm as it moves engaging and partially lodging behind said latch member to lock said switch in open position, and actuating means movable to engage and actuate said latch member to release said arm when said circuit is to be closed, said actuating means being operable from the recessed portion of said support and engageable by said patch plate when disposed in operable patch applying position, said actuating member comprising an axially movable plunger,

apartof whichis designedtorproject within-the:

recess in'a position to be' engaged by said patch applying plate, the otherpartsof which ispdis posed. partially to overlie said latch member and to-engage and displace saidelatch member when. depressed'by saidpatch plate, and meansfor" returning the actuator to-normal-'position.

5.- Patch vulcanizing apparatus comprisingrai support, a heating element-carried thereby, said support being recessed over an area'in its upper surface above said heating element, ,a patchlap plying plate mountable insaid recess-zto overlie the heating element designed to be heated-thereby, said :plate being adapted to carry a patch to: be zvulcanized to a rubberarticle, electric conduit;

means in connection with .said heating; element designed to form part of an electrical circuit for heatingathe-element, a: switch connected to said the path of movement of one end thereof, said bi-metal armbeing caused to move away-from said other arm to break said circuit Whensaid heating element is-heated to a predetermined degree, said bi-metal arm as it moves engaging and partially lodging behind said latch member to lock said switch in open position, andactuatingmeans movable toengage and actuate said latch member to release said'arm whensaid circuitis to'be closed, said actuating means being operable from the'recessed portion of said supportand engageable by said patch plate when disposed inoperable patch applying position, said: actuating member comprising an axially movable plunger, apart of which is designed to project within the recess in asposition-to beengaged .bysaid patch applying plate, the other part of which is disposed partially to overlie the latch memberland to en-.- gage'and displace said latch member -when. de-- pressed by said patch plate, said actuator-having a foot to engage said-latch member and push swingably to pass said' actuator when the latterf is displaced, said foot-being-formed with a sloping upper surface, and means for returning the actu ator to normal position,-said sloping surface of thefoot causing said actuator'to deflect past the latch member as it returns to normal position.-

6; In patch vulcanizing apparatus, an electrical heating'element designed to heat-a patch app,ly

ing plate for vulcanizing purposes, a thermostatic. switch controlling thecircuit for said element and designed .to open when said element has reached! a predeterminedheat, locking means for locking said switchopen as it moves to open position, and: means operable by the-patch applying plate when disposed in said apparatus in operable patch applyingposition for actuating said latch to release and close said switch.

7: Patch vulcanizing, apparatus comprising". a support, a heating element carried thereby, a: patch applying plate :mountable on said support: adjacentto the heating element and designed .to' beheated thereby, said plate being adapted to carrya patch to be vulcanized to a rubber article,- electric conduit-means in connection withsaid heating element anddesigned to form part of an: electrical circuit for heating the element, a switch v connected to said conduit means and including a pair of arms, one of which is-a bi-metal arm, saidarmshaving contacts normallyheld in engagement to complete the circuit, a latch member,- carried by said support adjacent to said bi-metal arm andpartiallyin the path of movement-of one end-thereof, said :bi-metal arm being causedto move away from said other arm to break said circuit when said element is heated to a prede termined degree, said bi-metal arm as itmoves engaging and partially lodging behind said latch member to lock said switch in openv position, and actuating means movable to engage and actuate said latch member to release said arm when said circuit isto be closed, said actuating means-be-- ing operable by said patch plate when disposed in. operable patch applying position.

ALFRED DANIEL SLATKIN.

REFERENCES CITED 9 The following references are of record in the file' of this patent:

UNITED STATES PATENTS of 1926 I 

